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BOUSSINESQ MODELLING OF NEARSHORE WAVES UNDER BODY FITTED COORDINATE

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Journal of Hydrodynamics 2012年第2期24卷 235-243页

作者： FANG Ke-zhao ZOU Zhi-li LIU Zhong-bo YIN Ji-wei State Key Laboratory of Coastal and Offshore Engineering Dalian University of Technology Dalian 116024China Key Laboratory of Coastal Disaster and Defence Ministry of Eduoation Hohai University Nanjing 210098China E-mail： kfang@***

A set of nonlinear Boussinesq equations with fully nonlinearity property is solved numerically in generalized coordinates,to develop a Boussinesq-type wave model in dealing with irregular computation boundaries in complex nearshore regions and to facilitate the grid refinements in *** governing equations expressed in contravariant components of velocity vectors under curvilinear coordinates are derived and a high order finite difference scheme on a staggered grid is employed for the numerical *** developed model is used to simulate nearshore wave propagations under curvilinear coordinates,the numerical results are compared against analytical or experimental data with a good agreement.

关键词： Boussinesq equation waves body fitted coordinate

I-doping of anodized TiO_2 nanotubes using an electrochemical method

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Chinese science Bulletin 2010年第20期55卷 2136-2141页

作者： SU YaLing XIAO YuTang DU YingXun FU Shiang Nanjing Institute of Geography and Limnology State Key Laboratory of Lake Science and Environment Chinese Academy of Sciences Nanjing 210008 China State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai University Nanjing 210098 China

In order to obtain TiO2 with high photocatalytic activity,a cathode reduction was used to dope I 7+ and I5+into TiO 2 nanotubes of anodized Ti in C2H2O4·2H2O+NH4F *** images show that the anodization method integrated the preparation with the doping process,which for nonmetals-doping is advantageous to maintain the morphological integrity of TiO2 nanotubes. I7+-I5+-doping enhances the UV response of TiO 2 and result in a *** UV/visible irradiation,a I7+-I5+-doped sample(400°C)showed the highest Iph and photocatalytic efficiency.A part of I - in the I7+-I5+-doped sample is involved in the UV re-sponse,the red-shift and the higher Iph.

关键词：二氧化钛纳米管电化学方法掺杂阳极氧化光催化活性可见光照射光催化效率紫外线

Online dynamic measurement of saturation-capillary pressure relation in sandy medium under water level fluctuation

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Journal of Central South university 2010年第1期17卷 85-92页

作者：李雁周劲风徐军 KAMON M School of Marine sciences Sun Yat-sen University Key Laboratory of Aquatic Food Product Safety of Ministry of Education Sun Yat-sen University School of Environmental science and Engineering Sun Yat-sen University College of Hydrology and Water Resources Hohai University Takamatsu National College of Technology

An online dynamic method based on electrical conductivity probe, tensiometer and datataker was presented to measure saturation-capillary pressure （S-p） relation in water-light nonaqueous phase liquid （LNAPL） two-phase sandy medium under water level fluctuation. Three-electrode electrical conductivity probe （ECP） was used to measure water saturation. Hydrophobic tensiometer was obtained by spraying waterproof material to the ceramic cup of commercially available hydrophilic tensiometer. A couple of hydrophilic tensiometer and hydrophobic tensiometer were used to measure pore water pressure and pore LNAPL pressure of the sandy medium, respectively. All the signals from ECP and tensiometer were collected by a data taker connected with a computer. The results show that this method can finish the measurement of S-R relation of a complete drainage or imbibition process in less than 60 min. It is much more timesaving compared with 10-40 d of traditional methods. Two cycles of water level fluctuation were produced, and four saturation-capillary pressure relations including two stable residual LNAPL saturations of the sandy medium were obtained during in 350 h. The results show that this method has a good durable performance and feasibility in the porous medium with complicated multiphase flow. Although further studies are needed on the signal stability and accuracy drift of the ECP, this online dynamic method can be used successfully in the rapid characterization of a LNAPL migration in porous media.

关键词： water level fluctuation saturation-capillary pressure (S-p) relation online dynamic measurement

Experimental Constraints on Formation of Low-Cr# Chromitite: Effect of Variable H2O and Cr2O3 on Boninitic-Magma and Harzburgite Reactions

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Journal of Earth science 2020年第4期31卷 709-722页

作者： Yage Zhao Yanfei Zhang Chao Wang Zhenmin Jin Qijin Xu College of Oceanography Hohai UniversityNanjing 210098China State Key Laboratory of Geological Processes and Mineral Resources China University of GeosciencesWuhan 430074China

Reactions between a boninitic or basaltic magma and harzburgite at shallow mantle depths are thought to be closely related to the formation of podiform chromitites,but little experimental data is available on these *** this study,a series of experiments were conducted at 1.5GPa and 1 000–1 400 oC to investigate the interactions between boninitic magma and harzburgite in homogenous mixed systems with varied bulk concentrations of water(~0.7 wt.%–10 wt.%)and Cr2O3(~0.2 wt.%–4 wt.%).In the experimental charges,chromite grains can be observed coexisting with orthopyroxene,clinopyroxene±olivine,and quenched melt in the Cr-bearing *** bulk concentration of Cr2O3 in the starting material has a slight effect on compositional changes in the chromites ***,the Cr#(Cr#=100×Cr/(Cr+Al))and Mg#(Mg#=100×Mg/(Mg+Fe))values for the chromites exhibit positive and negative correlations,respectively,with the bulk H2O *** 1 100 oC,chromite Cr#values range from^33–35 to^58–65,and chromite Mg#values range from^70–73 to^55–58when bulk H2O contents in the starting material are increased from^0.7 wt.%to^10 wt.%.The experimentally produced chromites have compositions(as expressed by Cr#,Mg#,and Ni O and Mn O contents)similar to natural chromites from low-Cr#chromitite *** suggest that the interactions between boninitic magmas with varied H2O contents and harzburgite in a shallow mantle wedge could be a possible mechanism that forms the low-Cr#chromitites found in *** emphasize here that H2O may play an important role in the compositional evolutions of natural chromitites.

关键词： low-Cr#chromitite boninitic magma harzburgite melt-rock reaction

Numerical study on the characteristics of flow field and wave propagation near submerged breakwater on slope

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Acta Oceanologica Sinica 2010年第1期29卷 88-99页

作者： CHEN Jie JIANG Changbo HU Shixiong HUANG Wenwei School of Hydraulic Engineering Changsha University of Science ＆ Technology Changsha 410114 China Hunan Province Key Laboratory of Water Sediment Sciences ＆ Flood Hazard Prevention Changsha 410114 China Department of Geography East Stroudsburg University of Pennsylvania East Stroudsburg PA 18301 USA School of Foreign Languages Changsha University of Science ＆ Technology Changsha 410114 China

In this study, characteristics of flow field and wave propagation near submerged breakwater on a sloping bed are investigated with numerical model. The governing equations of the vertical two-dimensional model are Reynolds Averaged Navier Stokes equations. The Reynolds stress terms are closed by a nonlinear k - ε turbulence transportation model. The free surface is traced through the PILC-VOF method. The proposed numerical model is verified with experimental results. The numerical result shows that the wave profile may become more asymmetrical when wave propagates over breakwater. When wave crest propagates over breakwater, the anticlockwise vortex may generate. On the contrary, when wave hollow propagates over breakwater, the clockwise vortex may generate. Meanwhile, the influenced zone of vortex created by wave crest is larger than that created by wave hollow. All the maximum values of the turbulent kinetic energy, turbulent dissipation and eddy viscosity occur on the top of breakwater. Both the turbulent dissipation and eddy viscosity increase as the turbulent kinetic energy increases. Wave energy may rapidly decrease near the breakwater because turbulent dissipation increases and energy in lower harmonics is transferred into higher harmonics.

关键词： submerged breakwater characteristics of flow field PLIC-VOF method sloping bed

Convergence and error estimate of cascade algorithms with infinitely supported masks in L_p(R^s)

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science China Mathematics 2012年第3期55卷 577-592页

作者： YANG JianBin LI Song Department of Mathematics College of Sciences Hohai University Nanjing 210098 China Department of Mathematics College of Sciences Zhejiang University Hangzhou 310027 China

The cascade algorithm plays an important role in computer graphics and wavelet *** this paper,we first investigate the convergence of cascade algorithms associated with a polynomially decaying mask and a general dilation matrix in L p (R s) (1 p ∞) spaces,and then we give an error estimate of the cascade algorithms associated with truncated *** is proved that under some appropriate conditions if the cascade algorithm associated with a polynomially decaying mask converges in the L p-norm,then the cascade algorithms associated with the truncated masks also converge in the L ***,the error between the two resulting limit functions is estimated in terms of the masks.

关键词： cascade algorithm polynomially decaying masks error estimate

Analysis of influence of observation operator on sequential data assimilation through soil temperature simulation with common land model

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Water science and Engineering 2018年第3期11卷 196-204页

作者： Xiao-lei Fu Zhong-bo Yu Yong-jian Ding Ying Tang Hai-shen Lü Xiao-lei Jiang Qin Ju College of Civil Engineering Fuzhou UniversityFuzhou 350116China State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai UniversityNanjing 210098China State Key Laboratory of Cryospheric science Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China Department of Geography Environmentand Spatial SciencesMichigan State UniversityEast LansingMI 48824USA

An observation operator is a bridge linking the system state vector and observations in a data assimilation system. Despite its importance, the degree to which an observation operator influences the performance of data assimilation methods is still poorly understood. This study aimed to analyze the influences of linear and nonlinear observation operators on the sequential data assimilation through soil temperature simulation using the unscented particle filter(UPF) and the common land model. The linear observation operator between unprocessed simulations and observations was first established. To improve the correlation between simulations and observations, both were processed based on a series of equations. This processing essentially resulted in a nonlinear observation operator. The linear and nonlinear observation operators were then used along with the UPF in three assimilation experiments: an hourly in situ soil surface temperature assimilation, a daily in situ soil surface temperature assimilation, and a moderate resolution imaging spectroradiometer(MODIS) land surface temperature(LST) assimilation. The results show that the filter improved the soil temperature simulation significantly with the linear and nonlinear observation operators. The nonlinear observation operator improved the UPF's performance more significantly for the hourly and daily in situ observation assimilations than the linear observation operator did, while the situation was opposite for the MODIS LST assimilation. Because of the high assimilation frequency and data quality, the simulation accuracy was significantly improved in all soil layers for hourly in situ soil surface temperature assimilation, while the significant improvements of the simulation accuracy were limited to the lower soil layers for the assimilation experiments with low assimilation frequency or low data quality.

关键词： Observation operator Unscented particle filter(UPF) Soil temperature MODIS LST Data assimilation

Trapping Mechanism of Submerged Ridge on Trans-oceanic Tsunami Propagation

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China Ocean Engineering 2016年第2期30卷 271-282页

作者：郑金海熊梦婕王岗 State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai UniversityNanjing 210098China College of Harbor Coastal and Offshore EngineeringHohai UniversityNanjing 210098China Nanjing Hydraulic Research Institute Nanjing 210029China State Key Laboratory of Coastal and Offshore Engineering Dalian University of TechnologyDalian 116023China The Key Laboratory of Water-Sediment sciences and Water Disaster Prevention of Hunan Province Changsha University of Science and TechnologyChangsha 410076China

Based on the linear shallow water equations,an analytic solution of trapped waves over a symmetric parabolicprofile submerged ridge is *** trapped waves act as propagating waves along the ridge and as standing waves across the *** amplitude gets the maximum at the ridge top and decays gradually towards both *** decaying rate gets more gently with higher ***,an explicit first-order approximate dispersion relation is derived to simplify transcendental functions in the exact solution,which is useful to describe trapped waves over shallowly submerged ridges in ***,the trapping mechanism of the submerged ridge waveguides on the trans-oceanic tsunami propagation can be explained by the ray theory.A critical incident angle exists as a criterion to determine whether the wave is ***,a trapped parameter γ is proposed to estimate the ratio of the energy trapped by the oceanic ridge if a tsunami is generated at its top.

关键词： trapped waves guided waves shallow water equations analytical solutions tsunamis

Wireless environmental monitoring system for transformer substation based on acoustic sensor

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High Technology Letters 2012年第4期18卷 394-400页

作者：朱昌平 Huang Yon.gliang Shan Minglei Jiangsu Key Laboratory of Power Transmission and Distribution Equipment Technology Hohai University Changzhou 213022 P. R. China

In this paper, an indoor environmental monitoring solution is proposed for the transformer sub- station system by using the ZigBee technology. It mainly analyzes the principle of sulfur hexafluoride sensor based on the acoustic method and puts forward a difference data processing method of single- channel and temperature compensation point at power consumption issues for sensor detection. The method not only reduces the sensor power consumption, but also ensures the accuracy and extends the lifetime of wireless sensor nodes effectively. This paper also analyzes the design of the base sta- tion mode, and demonstrates the running processes of routers and sensors. The feasibility of the pro- posed approach has been testified and proved.

关键词： environmental monitoring acoustic sensor ZigBee wireless network CC2430